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MECHANISM FOR STRAIGHTENING AND KEEPING STRAIGHT BAND KNIVES AND SAWS.

No. 284,957. atented Sept. 11, 1883.

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S. E. 82; J. E. FURLONGI MECHANISM FOR STRAIGHTENING AND KEEPING STRAIGHT BAND KNIVES AND SAWS.

No. 284,957. Patented Sept. 11, 1883.'

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s. E. & J. E. FURLONG. MECHANISM FOR STRAIGHTENING AND KEEPING STRAIGHT BAND KNIVES AND SAWS.

' No 284,957, Patented Sept. 11, 1883.

C7 7 F'Tgfi INF/inlggfifi MTNEEEEE i 55x27 Ma da 7 iTE SIMON E. FURLONG AND JAMES E. FURLONG, OF VOBURN, MASS.

MECHANISM FOR STRAIGHTENING AND KEEPING STRAIGHT BAND KNIVES AND SAWS.

' SPECIFICATION forming part of Letters Patent No. 284,957, dated September 11, 1883,

Application filed Juiy 24, 1682. (NomodeL) To all whom it ntay concern:

Be it known that we, SIMON E. FURLONG and JAMES E. FURLO-NG, both of Woburn, in the county of Middlesex and State of Massachusetts, citizens of the United States, have made a certain new and useful Mechanism for Straightening and Keeping Straight Band- Knives, 850., of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, in which like letters indicate corresponding parts.

The nature of our invention appertains more especially to that class of machines in which bands, or band-saws, or band-knives are used in cutting, sawing, or splitting leather or other articles, and is more particularly confined to a novel arrangement of grinders in connection with adjustable guides by which the band is I kept of uniform width throughout, and by which means the nicety of adjustment and regulation of the band-knife or band-saw in relation to the substance to be cut or sawed can be regulated. u I Figure 1 is a side elevation of a machine in which the principal parts are shown. Fig. 2 is an end elevation taken at w w of Fig. 1. Fig. 3 represents in detail the grinders in sectionx 00 of Fig. 1. Fig. 4 represents the front grinders in relation to the adjustable guides in section at y y of Fig. 1. Fig. 5 is also an end elevation of a machine in which the adjustable guide and back grinder, in relation to the other parts of the machine, are more particularly shown.

The form shown in Figs. 1, 2, and 5 represents in general structure a machine adapted to carry a band knife or saw such as is in ordinary use.

B B are the band-wheels over which the band A travels and is carried while working.

- Upon one edge of the band-wheels B is the rim 7), against which the back of the band presses and which aids and steadies the band while cutting. The band A is further held in its position by adjustable guides placed in designated positions, as represented by d d dd, and which guides are represented in, detail in Fig. 4 and to some extent in Fig. 5.

D is the frame of the machine; 6, the main driving-pulley; f, the belt. The back grinding-wheel, G, revolves on the spindle or arbor c in the bearing 0, and is driven by the belt 0" upon the pulley c from the driving-pulley a, resting upon the shaft 0 and revolved by the belt 0 Upon the belt 0 is placed an idler c". The grinder O, with its arbor and bearings, is held in positionin the bracket .0 which is bolted to the frame of the machine D. This grinder Ois made adjustable bythe screw 0" in connection with its bearing-blocks 0; and the screw is turned by the handwheels a a, by which means the grinder is moved laterally to and from the back of the cutting-blade. This grinder is preferably placed so that the plane of the line of the diameter of the grinder shall coincide with the back of the band. Of course the grinder may be used in other positions; but the one stated, andrepresented in the drawings, is preferable.

E E are grinders placed in the usual manner to revolve against the cuttingedge of the band in order to sharpen it. These grinders are made adjustable in any convenient manner to compensate for the wear of the circumference of the grinders. All of the grinders .75 are preferably made of emery or a similar substance.

In Fig. 4. is represented in section one of the adjustable guides through which the bandknife passes. cl is the guide; d, the opening or mouth through which the band A passes as it is revolved upon the carrying-pulleys B. a is a screw working in the body of the guide (Z, which is turned by the thumb-wheel a.

In operating a machine of this character it is of the utmost importance that the band, should run as nearly true and even inrelation to the work as possible, and as the distance from the cutting-edge of the band to the cutting-table would naturally be a variable distance, on account of the wear of the band, it is customary to provide for aliberal adjustment of the main driving-pulleys B upon theirshafts, so that while the back of the band is alwayspressed against the shoulder b the cutting-' edge shall remain at the same distance from the cutting-table upon which the leather or other article to be cut or sawed is placed. In

cutting or splitting leather particularly it is of the utmost importance that the cuttingedge of the band shall be at a uniform distance from the cutting-table; but in conse- IOO - by analogous devices.

quence of the stretching of the band, the inequalities in the temper, and from many other causes, it is .found that both short and long twists or joints are formed in the band. To overcome this difficulty the only means heretofore known has been to set up the guides and to grind off the cutting-edge of the bands to form as uniform a cutting-surface as possible; but on account of the reasons heretofore stated, and because the band is stretchedvery tight, and the varying density of the article to be cut, and other causes, it has been found impossible to keep the cutting-bandperfectly true and even upon its. cutting edge, and to uniformly run at a' given distance from the cutting-table or article to be operated upon. The front grinders are primarily for sharpening the band, and perform the operation of straightening or truing the band incidentally, but very imperfectly, as heretofore used. We have ascertained that the difficulty of correctly truing and keeping true a band saw or knife in condition to perform fine work is probably because the irregularities which come by use render the back of the band uneven, and as it passes over the band-wheels and through the guides the cutting-edge is constantly varying. After the band has been in use any considerable length of time, the only way to put it in working condition, according to our experience, is to grind the back of the band by the means herein described, or

Therefore to overcome those objections we have found by long experience and experiment that by applying the device which we have heretofore described to the back of the blade while upon the machine, in connection with the adjustable guides ,and in connection with the bandsharpeners E IE, it is possible to maintain a band knife orsaw in perfect condition, and with a perfectrunning cutting-edge in relation to the articles to be cut, whereby a large saving is made in the band knives and saws them selves, and a great saving of time in keeping the bands in proper condition, and, further, in reducing the amount of poor orindifferent work to the minimum.

It will be observed that the adjustable grinder C is always placed so that it will operate upon the back edge of the band, while the sharpening-grinders E E are placed upon the opposite or cutting side of the band, preferably not far apart, and in relation to the adjustable guides as heretofore stated.

We have found that the only possible mode of keeping the cutting-edge of the band in perfect condition was by also grinding and truing the back as well as the cutting-edge of the.

band. This we are not aware has ever been deemed practicable before our invention, or, if it could be done',that it would have any desirable effect upon the running of the band itself. The device wehave heretofore explained performsthis work while the band is upon the machine and running, and overcomes the great difficulties hitherto encountered in doing fine work with a band-knife, substantially as heretofore practiced.

As previously stated, it is important that the back grinder should have its cutting-surface contact with the band on the line and parallel plane of the diameter of the grinder, in order to avoid, as far as possible, the tendency to spring the band, the work being done while the band itself is running. There would also be danger of springing it unless carefully steadied and supported by the adjustable guides. The front grinders, working against each other to sharpen or bevel the band, do not act upon the band with the same effect as the back grinder in its position as shown. The

tendency of the action of the back grinder, is to press the band from the band-wheels. This is overcome by using the front grinders or sharpeners in connection with the back grinder. The back grinder is used less than the front sharpeners, so that the back of the band can be kept straight without wearing away the front of the band unnecessarily. It isobvious that it is not practicable to operate the back grinding device to do any severe work without the support given to the band by the front grinders working at the same time. Thus while the front sharpeners may be used to sharpen the band alone, the back grinders cannot be be used, except to a very limited extent, without also using the front sharpeners in connection therewith. This must be apparent to any mechanic upon an inspection of the bandcarrying wheels, and the manner in which the band is driven and supported on the bandwheels.

It will be noticed that in the construction of the back grinder, as shown, the back of the moving band is across the face of the grinder, and the tendency of the grinder is-to not only press the band forward upon the band-wheels, but also to press theband either downwardly or upwardly, according as the grinder isrevolved. To overcome this latter vibration it is al ways necessary to carefully adjust the guides, that the band may not be sprung or broken. It is possible that if the back grinder were placed flatwise, and made to revolve in the same line as the band, the guides might be dispensed with in the same operation, but even in this position of the grinder the guides would still aid in steadying the band and materially assist in truing the same. We prefer, however, the construction shown in the drawings, deeming it the best for many reasons.

We claim- 1. The combination of the band-wheels and means for supporting and rotating them, and

a band knife or saw, with a grindstone adjustnation with the adjustable band-wheels B, sub

stantially as and for the purposes set forth.

3. In an organized machine; the adjustable grinder 0, adapted to revolve and operate upon a moving band-knife, in combination with the adjustable cutters or grinders E E, substantially as and for the purposes set forth;

4. In combination, the adjustable grinder O and the adjustable guides (1, both adapted to operate in combination with each other and upon the back of a revolving band knife or IO saw, substantially as and for the purposes set forth.

5. In an organized band cutting machine, 

